Process for breaking petroleum emulsions



Patented Jan. 27, 1953 OFF ICE PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groo-te, University City, MO., assignmto Petrolite Corporation, a corporation of Delaware No Drawing. Application May 14., 19.5.1, Serial No. 226,310

11 Claims. 1

The present invention is a continuation-in-part of my copending applications, Serial Nos. 104,801, filed July 14, 1949 (now Patent 2,552,528, granted May 15, 1951) 109,619, filed August 10, 1949 (now Patent 2,552,531, granted May 15, 1951 and 107,381, filed July 28, 1949 (now Patent 2,552,530, granted May 15, 1951). This invention relates to petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continu ous phase of the emulsion.

One object of my invention is to provide a novel process for breaking or resolving emulsions of the kind referred to. Another object of my invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned are of significant value in removing impurities, particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes the preventive step of commingling the demulsifier with the aqueous component which would or might subsequently become either phase of the emulsion, in absence of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractional ester obtained from a polycarboxy acid and a polyhydroxylated ma-. terial obtained by the oxypropylation of a polyamino reactant.

More specifically the present process involves the use of a demulsifying agent which is an acidic acylation product obtained from a polycarboxy acid with a compound derived in turn by the oxypropylation of dipropylenetriamine or .an equivalent triamine as hereinafter specified, having a plurality of terminal hydroxyl radicals or the equivalent, i. e., labile hydrogen atoms susceptible to oxyalkylation.

The most suitable raw material is dipropylenetriamine or such product treated with several moles of ethylene oxide or glycide, or a combina tion of the two, and particularly dipropylenetriamine treated with one to five, six or seven moles of ethylene oxide. The initial triamino com pound must be characterized by (a) having 3 amino nitrogen atoms and preferably all being basic; (1)) free. from any radical having 8 or more carbon atoms in an uninterrupted group; (c). must be Water-soluble; (d). have a plurality of re active hydrogen atomspreferably at least 3 or 4; and (6) must have a molecular weight not over The oxypropylated derivatives of such triamines, which are reactive with polycarboxy acids to produce compounds used in accordance. with the present invention, must have a molecular weight within the range of 2500. to 30,000, must be water-insoluble, kerosene-soluble, must have a ratio of propylene oxide to reactive hydrogen atoms of the triamino compound in the range. of 7 to 70, and the triamino compound mustrepresent not more than 20% 'by weight of the oxypropylated product, the ratios and molecular weights specified being on a statistical basis and based on an assumption of complete reaction between the triamine and the, propylene oxide.

When forming the acylation products, thev polycarboxy acid is used in a molar ratio of one, mole of polycarboxy acid for each reactive hydrogen of the oxypropylated triamino compound.

For reasons which will be p.ointed out,.I believe the products are of essentially fractional esters, but may to some extent have an amide structure and in addition, because of the. fact that one or more of the nitrogen atoms are, advantageously basic, may also be in the form of ester salts. For this reason they are referred to above as acylation products, and for this reason in the claims the products are referred to as being selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives.

Needless to say,vv the, most readily available re: actant, to Wit, dipropylenetriamine, has 5 reactive hydrogen atoms, and this still would. be true after reaction with ethylene oxide, for instance, 5 moles of ethylene oxide. However, reaction with glycide would provide as many aslO reactive hydrogen atoms provided that the molal ratio was still the same. as before. to wit, 5. moles of glycide for one mole of triamine. 0.1 the other hand, if dipropylenetriaminewere treated with an alkylating agent so as. to intro duce an alkyl radical such as methyl, ethyl, propyl, butyl, l. ep yl, r the l k or an, ary dical su h as a ph nyl a c then. and in that. event the number of reactive hydrogen atoms might be decreased to as few as two and still be acceptable for t instant pu pos I an alky .radical or an ali y li radi al, u h as a cy lohexyl radical. or an alkylary rad ca s ch as a b njz lflradica were introduced the basicity of the nitrogen atom would not be materially aifected. However, the introduction of a phenyl radical would, of course, markedly affect the basicity of the nitrogen atom. For obvious reasons my choice is as follows:

(a) The use of dipropylenetriamine rather than any substituted dipropylenetriamine as described; (17) the use of dipropylenetriamine after treatment with 1 a 5 moles of ethylene oxide although a modestly increased amount of ethylene oxide can be used in light of what is said hereinafter; or (c) the use of a derivative obtained from dipropylenetriamine after reaction with glycide, or a mixture of ethylene oxide and glycide.

Since reaction of dipropylenetriamine with propylene oxide is invariably involved and since thi oxyalkylation step is substantially the same as the use of ethylene oxide or glycide, for the purpose of brevity further reference simply will be made to dipropylenetriamine as illustrating the procedure, regardless of what particular reactant is selected. It is not necessary to point out, of course, that the substituted dipropylenetriamine, i. e., those where an alkyl, alicyclic, aryl-alkyl, or aryl group has been introduced can similarly be subjected to reaction with ethylene oxide, glycide, or a combination of the two.

I also want to point out it is immaterial whether the initial oxypropylation step involves hydrogen attached to oxygen or hydrogen attached to nitrogen. The essential requirement is that it be a labile or reactive hydrogen atom. Any substituent radical present must, of course, have less than 8 uninterrupted carbon atoms in a single group.

Reference to the products as fractional esters may be, and probably would be, an over-simplification for reasons which are obvious on further examination. It is pointed out subsequently that prior to esterification the alkaline catalyst can be removed by addition of hydrochloric acid. Actually the amount of hydrochloric acid added is usually suflicient and one can deliberately employ enough acid, not only to neutralize the alkaline catalyst but also to neutralize the amino nitrogen atom or convert it into a salt. Stated another way, a trivalent nitrogen atom is converted into a pentavalent nitrogen atom, i. e., a change involving an eleotrovalency indicated as follows:

N- BK g wherein HX represents any strong acid or fairly strong acid such as hydrochloric acid, nitric acid, sulfuric acid, a sulphonic acid, etc., in which H represents the acidic hydrogen atom and X represents the anion. Without attempting to complicate the subsequent description further it is obvious then that one might have ester or one might convert the esters into ester salts as described. Likewise another possibility is that under certain conditions one could ob tain amides. The explanation of this latter fact resides in this observation. In the case of an amide, such as acetamide, there is always a question as to whether or not oxypropylation involves both amido hydrogen atoms so as to obtain a hundred per cent'yield of the dihydroxylated compound. There is some evidence to at least some degree that a monohydroxylated compound is obtained under some circums a c with one amido hydrogen atom remaining with out change.

Another explanation which has sometimes appeared in the oxypropylation of nitrogen-containing compound particularly such as acetamide, is that the molecule appears to decompose under conditions of analysis and unsaturation seems to appear simultaneously. One suggestion has been that one hydroxyl is lost by dehydration and that this ultimately causes a break in the molecule in such a way that two new hydroxyls are formed. This is shown after a fashion in a highly idealized manner in the following way:

In the above formulas the large X is obviously not intended to signify anything except the central part of a large molecule, whereas, as far as a speculative explanation is concerned, one need only consider the terminal radicals, as shown. Such suggestion is of interest only because it may be a possible explanation of how an increase in hydroxyl value does take place which could be interpreted as a decrease in molecular weight. This matter is considered subsequently in the final paragraphs of Part 2. This same situation seems to apply in the oxypropylation of at least some polyalkylene amines and thus'is of significance in the instant situation.

In the case of higher polyamines there is evidence that all the available hydrogen atoms are not necessarily attacked, at least under comparatively modest oxypropylation conditions, particularly when oxypropylation proceeds at low temperature as herein described, for instance, about the boiling point of water. For instance, in the case of diethylene triamine there is some evidence that one terminal hydrogen atom only in each of the two end groups is first attacked by propylene oxide and then the hydrogen atom attached to the central nitrogen atom is attacked. It is quite possible that three long propylene oxide chains are built up before the two remaining hydrogens are attacked and per haps not attacked at all. This, of course, de pends on the conditions of oxypropylation. However, analytical procedure is not entirely satisfactory in some instances in differentiating between a reactive hydrogen atom attached to ni trogen and a reactive hydrogen atom attached to oxygen.

If this is the case it is purely a matter of speculation at the moment because apparently there is no data which determines the matter completely under all conditions of manufacture, and one has a situation somewhat comparable to the acylation of monoethanolamine or diethanolamine, i. e., acylation can take place involving either the hydrogen atom attached to oxygen or the hydrogen atom attached to nitrogen.

As far as the herein described compounds are concerned it would be absolutely immaterial exoept that one would have in part a compound which might be the fractional ester and might also represent an amide in which only one carboxyl radical of a polycarboxylated reactant was involved. By and, large, it is believed that the materials obtained are. obviously fractional'esters, for reasons which are apparent in light of what has been said and in light of what appears hereinafter.

Whathas been said inregard to the reactions involving polyethyleneamines obviously is true in regard to polypropyleneamines.

For convenience, what is said hereafter will be divided into four parts:

Part 1 is concerned with the preparation of the oxypropylation derivatives of dipropylenetriamine or equivalent initial reactants;

Part2 is concerned with the preparation of the estersfrom the oxypropylated derivatives:

Part 3 is concerned with the nature of the oxypropylation derivatives insofar that a cogeneric mixture is invariably obtained, and

Part 4: is concerned with the use of the products herein described as demulsifiers for break-- ing water-in-oil emulsions.

PART 1 For a number of well known reasons, equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as a rule designed for aparticular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant sizethe design is such as to use any of the customarily available alkylene oxides, i. e., ethylene oxide, propylene .oxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard tothe time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as for example 95 to 120 C. Under such circumstances. the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is sometimes the case, to wit, keeping an atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperature-low reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664 to H. R. Fife et al., dated September '7, 1948. Low temperature, low pressure oxyp-ropylations are particularly desirable where the compound being subjected to oxypropylation contains one, two or three points of reaction only, such as mcnohydric alcohols, glycols andtriols.

The initial reactants in the instant application contain at least two reactive hydrogens and for this reason there is possibly less advantage in using low temperature oxypropylation rather than high temperature oxypropylation. However, the reactions do not go too slowly and this particular procedure was used in the subsequent examples.

Since low pressure-low temperature low-reaction-speed oxvpropylations, require considerable time, for instance, 1 to 7 days of 24 hours-each to complete the reaction they are conducted as a rule whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatical- 1y. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features: (a) a solenoid controlled valve which shuts off the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, to C., and (b) another solenoid valve which shuts off the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to 35 pounds. Otherwise, the equipment is substantially the same as is commonly employed for this purpose where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant equipment which is designed to permit continuous oxyalkylation whether it be oxypropylation or oxyethylation. With certain obvious changes the equipment can be used also to permit oxyalkylation involving the use of glycide where no pressure is involved except the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out the method of using propylene oxide is the same as ethylene oxide. This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation of the oxyalkylated deriva tives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure was em ployed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately 15 gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variablespeed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide, to'the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling jacket, and, preferably, coil in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, of course, in essence small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity. for instance, approximately 3 liters in one case and about 1 gallonsin another case, was used.

Continuous operation, or substantially con tinuous operation. was achieved by the use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, tlie container consists essentially of a laboratory bomb having a capacity ofabout one-halt gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about '60 pounds was used in connection with the 15-ga1lon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer, connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings'could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for instance, if 105 C. was selected as the operating temperature the maximum point would be at the most 110 C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds within a -pound variation one way or the other, but might drop to practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 0. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days ('72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation i concerned. The minimum time recorded was about a 6-hour period in a single step. Reactions indicated as being complete in 7 or 8 hours may have been complete in a lesser period of time in light of the automatic equipment employed. In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the propylene oxide if fed continuously would be added at a rate so that the predetermined amount would react within the first 5 hours of the 8-hour period or two-thirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop the predetermined amount of oxide would still be added in most instances well within the predetermined time period. Sometimes where the addition was a comparatively small amount in an 8-hour period there would be an unquestionable speeding up of the reaction, by simply repeating the example and using 4, 5 or 6 hours instead of 8 hours.

When operating at a comparatively high temperature, for instance, between 150 to 200 C., an unreacted alkylene oxide such as propylene oxide, makes its presence felt in the increase in pressure or the consistency of a high pressure. However,

at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for unreacted propylene oxide. One obvious procedure, of course, is to oxypropylate at a modestly higher temperature, for instance, at to C. Unreacted oxide afiects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time required to add a given amount of oxide. One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as a week or ten days time may elapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two hours so that reaction continued for 1 to 3 hours after the final addition of the last propylene oxide and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well as on large scal size. This final stirring period is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the. propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow continuous run which was shut oil" in case the pressure passed a predetermined point as previously set out. All the points of design, construction, etc., wer conventional including the gauges, check valves and entire equipment. As far as I am aware at least two firms, and possibly three, specialize in autoclave equipment such as I have employed in the laboratory, and are prepared to furnish equipment of this same kind. Similarly pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specially designed for the purpose.

It is to be noted in the present instance one may or may not have basic nitrogen atomspresent. For example, if a phenyl radi-cal is attached to each nitrogen atom the initial triamine is substantially nonbaslc. However, if one employs dipropylenet-riamine there are present three basic nitrogen atoms and thus the addition of an alkaline catalyst can be eliminated in the early stages Example 1a The particular autoclave employed was one with a capacity of approximately gallonsor on the average of about 125 pounds of reaction mass. The speed of the stirrer couldbe varied from 150 to 350 R. P. M. The initial charge was 7 pounds of dipropylene triamine. Even though this reagent itself is alkaline .75 pound of caustic soda was added. The reaction pot was flush-ed out with nitrogen, the autoclave sealed,and the automatic devices set for injecting 57 pounds of propylene oxide in approximately '9 hours. The pressure regulator was setior a maximum of -37 pounds per square inch. However, in this particular step and in all succeeding steps the pressure rarely got this high. Intact, the bulk of the reaction could take place, and-probably did take place, at an appreciably lower pressure. This comparatively low pressure was the result of the fact that the reactant per se was basic and also because considerable catalyst was added. The propylene oxide was added rather slowly at the rate of about 7 pounds per hour, and more important, the selected temperature was within the range of 250 to 260 F. (moderately higher than the boiling point of water). The initial introduction of propyleneoxide was not started until the heating devices had raised the temperature to about 240 F., somewhat higher than the boiling point of water. At the completion of the reaction a sample was taken and oxypropylation continued as in Example 20 immediately following.

Exampl 2a 36.26 pounds of reaction mass identified as Example la, preceding, and equivalent to 3.92 pounds of the polyamine, 31.92pounds of propylene oxide and .42 pound of caustic soda, were subjected to reaction with 27.99 pounds of propylene oxide. No additional catalyst was added. The oxypropylation was conducted in substantially the same manner in regard to temperature and pressure as in Example 1a, preceding. The time period was shorter. to wit, about 2 hours. The oxide was-added fairly rapidly, about 15 to as Example 2a, preceding, equivalent to 2.79 pounds of the polyamine, 42.66 pounds of propylene oxide, and .30 pound of caustic soda, were subjected to further oxypropylation in the same manner as described in the two preceding examples. No additional catalysts were introduced. The amount of propylene oxide added was 27.25 pounds. The conditions of reaction as far as temperature and pressure were concerned were the same as in the two preceding examples. The time period was 3 hours. The oxide was added at the rate of a little over 10 pounds per hour. When the reaction was complete part of the sample was withdrawn and the remainder subjected to further oxypropyl-ation as described in Example 4d, immediately following.

Example 4a 43.75 pounds of the reaction mass identified as Example 3a, preceding, and equivalent to 1.67 pounds of the polyamine, 41.90 pounds of propylene oxide and .18 pound of caustic soda were subjected to further oxypropylation. No additional catalyst was added. Conditions as far as temperature and pressure were concerned were the s-ame as in the two preceding examples. The time period was 4 hours. The amount of oxide added was 26.75 pounds. The oxide was added at the rate of about 10 pounds per hour. At the completion of the reaction part of the sample was withdrawn and the remainder subjected to further oxypropylation as described in Example 5a, immediately following.

Example 5a 49 pound-s of reaction mass identified as Example 4a, preceding, and equivalent to 1.16 pounds of the polyamine, 47.72 pounds of propylene oxide, and .12 pound of caustic soda, were subjected to further oxypropylation without the addition of any more catalyst. Conditions as far as temperature and pressur were concerned were the same as in preceding examples. The amount of oxide added was 15.75 pounds. This oxide was added in 4 hours at the rate of about 5 to 6 pounds per hour.

What has been said herein is presented in tabular form in Table 1 immediately following with some added information as to molecular weight and as to solubility of the reaction prod not in water, xylene and kerosene.

TABLE 1 Composition'Before Composition at End MBW. M Max. EL y ax. Pres, Time, N0 Amine Oxide Cata- Theo. Amine Oxide Cata- 5%? 532 Hrs.

Amt, Amt, lyst, Moi. Amt, Amt, lyst,

lbs. lbs. lbs. Wt. 5 lbs. lbs.

la 7.0 .75 1,200 7.0 57.0 .75 1,032 250-260 35-37 0 2a-- a 92 31.92 .42 2,130 3.92 50. 91 .42 1,140 250-260 35-37 2 3a,- 2.70 p 42. 66 .30 3,410 2. 79 69.91 .30 1,632 250-260 35-37 2 4a 1.67 41.90 .18 5,510 1.67 68.65 .18 2175 250-260 3537 4 5a- 1.16 47. 72 .12 7,290 1.16 63.47 .12 2, 742 250-260 35-37 4 45.75 pounds of the reaction mass identified Example la was soluble in water and xylene, but insoluble in kerosene; Example 2a was emulsifiable'in water, soluble in xylene but insoluble in kerosene; Examples- 3a and 400' were both insoluble in water, soluble in xylene and insoluble in kerosene; and Example 505 was insoluble in water, but soluble-in both xylene and kerosene.

Referring to the first series of compounds, Examples la through a, in a similar series I have prepared compounds in which the theoretical molecular weights ran as high as 9,000 to 12,000 with hydroxyl molecular weights running from in excess of 3,000 to 4,000. Under these circumstances the products prior to esterification were water-insoluble, xylene-soluble and kerosene-soluble.

The final product, i. e., at the end of the oxypropylation step, was apt to be either a faint straw color, or sometimes it would have a more definite dark amber to black-reddish tinge. In the later stages the product was invariably Water-insoluble and kerosene-soluble. This is characteristic of all the products obtained from the triamino products herein described. Needless to say if more ethylene oxide radicals were introduced into the initial raw material the initial product is more water-soluble and one must go to higher molecular weights to produce water-insolubility and kerosene-solubility, for instance, molecular weights such as 8,000 to 12,000 or more on a theoretical basis, and 3,000 to 4,000 or 5,000 on a hydroxyl molecular weight basis. If, however, the initial triamino compound is treated with one or more or perhaps several moles of butylene oxide then the reverse effect is obtained and it takes less propylene oxide to produce water-insolubility and kerosene-solubility. These products were, of course, alkaline due in part to the residual caustic soda employed. This would also be the case if sodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene such solubility test can be made simply by shaking small amounts of the materials in a test tube with water, for instance, using 1% to 5% approximately based on the amount of water present,

Needless to say, there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater'than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difficulty is encountered in the manufacture of the esters as described in Part 2 the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a matter of common knowledge and requires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

PART 2 As previously pointed out the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly tricarboxy acids like citric and dicarboxy acids such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacic acid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconic acid or anhydride, maleic acid or anhydride adducts as obtained by the Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be heat stable so they are not decomposed during esterification. They may contain as many as 36 carbon atoms as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarboxy fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any other obvious equivalents. My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acids and glycols or other hydroxylated compounds is well known. In the present instance the hydroxylated compounds obtained as described in Part 1, preceding, contain nitrogen atoms which may or may not be basic. Thus, it is probable particularly where there is a basic nitrogen atom present that salts may be formed but in any event under conditions described the salt is converted into an ester, This is comparable to similar reactions involving the esterification of triethanolamine. Possibly the addition of an acid such as hydrochloric acid if employed for elimination of the basic catalyst also combines with the basic nitrogen present to form a salt. In any event, however, such procedure does not affect conventional esterification procedure as described herein.

Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acylchloride, etc. However, for purposes of economy it is customary to use either the acid or the anhydride. A conventional procedure is employed. 0n a laboratory scale one can employ a resin pot of the kind described in U. S. Patent No. 2,499,370, dated March 7, 1950, to De Groote and Keiser, and particularly with one more opening to permit the use of a porous spreader if hydrochloric acid gas is to be used as a catalyst. Such device or absorption spreader consists of minute alundum thimbles which are connected to a glass tube. One can add a sulfonic acid such as paratoluene sulfonic acid as a catalyst. There is some objection to this because in some'instances there is some evidence that this acid catalyst tends to decompose or rearrange the oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, which is strongly acidic there is no need to add any catalyst. The use of hydrochloric acid gas has one advantage over paratoluene sulfonic acid and that is that at the end of the reaction it can be removed by flushing out with nitrogen, whereas there is no reasonably convenient means available of removing the paratoluene sulfonic acid or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at an exceedingly slow rate so as to keep the reaction mass acidic. Only a trace of acid need be present. I have employed hydrochloric acid gas or the aqueous acid itself t eliminate the initial basic material. My preference, however, is to use no catalyst whatsoever.

The products obtained in Part 1 preceding may contain a basic catalyst. As a general procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The

mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation stops. This preliminary step can be carried out in the flask to be used for esteriflcation. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may be required. In any event the neutral or slightly acidic solution of the oxypropylated derivatives described in Part, 1 is then diluted further with sufiicient xylene, decalin, petroleum solvent, or the like, so, that. one has obtained approximately a 45% solution.

To this solution there is added a,.polycarboxylated.

reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglyco'llicz acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination.

Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end product can then be acidified with just enough concentrated hydrochloric acid or just neutralize the residual basic catalyst. T this product one can then add a small amount of anhydrous sodium sulfate (sufficient in quantity to take up any water that is present) and then subject the mass to centrifugal force so as to eliminate the hydrated sodium sulfate and probably the sodium chloride formed. The clear, somewhat viscous dark-colored amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride but, in any event, is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the productshere described are not polyesters in the sense that there is a plurality of both triamin radicals and acid radicals; the product is characterized by having only one triamino radical.

In some instances and, in fact, in many. instances I have found that in spite of the dehydration methods employed above that a mere trace of water still comes through and that this mere trace of water certainly interferes with theacetyl or hydroxyl value determination, at least when a number of conventional procedures are usedand may retard esteriflcation, particularly where there is no sulfonic acid or hydrochloricacid present asa catalyst. Therefore, I have; preferred to use the followingprocedure: I have employed about 200 grams of the polyhydroxylated compound asdescribed in Part 1, preceding; I have added about 60 gramsofbenzene, and then refluxed this mixture inthe glass resin pot using a phase-separating trap untilthe benzene carried out all the water present as water of solutionor the, equivalent. Ordinarily thisv refluxing temperature is apt to bein the. neighborhood of130 to possibly 150. C. When all this wateror moisturev has been removed I also withdraw approximately '20: grams or alittle less benzene and then add, the required amount of the carboxy reactant and also about 150 grams of a high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent effect act as if they were almost completely .aromatic in character. Typical distillation data in the particular type I have employed and found very satisfactory is the following:

I. B. P., 142 0. m1., 242 C.

5 ml., 200 0. ml.-, 244 c. 10 ml., 209 0. ml., 248 0. 15 ml., 215 C. ml., 252 0. 20 ml., 216 0. ml., 252 0. 25 ml., 220 c. '15 ml., 260 c. 30 ml., 225C. m1, 264 c. 35 ml.,- 230 0. ml., 270 0. 40 ml., 234 0'. mi, 280 0. 45 ml., 237C. ml., 307 0.

After this-materialisadded, refluxing is continued and, of course, is at a higher temperature, to Wit, about to C. If the carboxy reactant is an anhydride. needless to say no water of reaction appears; if the carboxy reactant is an acid, water 'of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated I simply separate out another 10 or 20 cc. of benzene by means of the phase-separating trap and thus raise the temperature to or C., or even to 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory provided one, does not attempt to remove the solvent subsequently except by vacuum distillation and provided there is no objection to a little residue. Actually, when these materials are used for a purpose such as demulsifi'cation the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin or an alkylated decalin which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

In a number of examples comparable to the series immediately following I have employed the #7-3 solvent instead of xylene. However, xylene alone is perfectly satisfactory where the initial product shows comparatively littleor'no water? solubility. For-instance, Example 2a previously referred to was emulsifiable in water. but not en-' tirely water-soluble. Thus, in Examples 7b through 30b, I have found xylene alone to be perfectly satisfactory because the initial polyhydric material was either entirely water-insoluble or at the most water-emulsiflable. However, in Examples 12; through 61) I have used a xylenemethanol mixture. In such instances xylene was used to the extent of two-thirds of-the solvent indicated and when all the water was eliminated approximately 35% methanol was added. In this instance ahomogeneous solution was obtained. Here, again, any suitable variant'eould be employed.

Another obviousprocedure, of course, is merely to distill off a solvent such as'xylene orSolvent #7-3 and then dissolve the product n a semipolar solvent, such as methanol, ethanol, propanol, etc. It is purely a matter of convenience first to employ a non-polar solvent (water-insoluble) to eliminate the water during distillation and then add a suitable polar solvent (hydrophile) togive a single-phase system.

TABLE 2 Theo. M01. Amt. of Ex. Ex. M01. & Actual Wt. g Pol fit g ggi X; droxyl fg gi CHyd Polycarboxy Reactant gg??? Ester Ompd H. 0. value of Value Actual ant H. v. (e a) (grs la 1, 200 140 163 1, 032 193 Diglycolic Acid 75. 0 1a 1, 200 140 163 1, 032 193 Oxalic Acid 70. la 1, 200 140 163 1, 032 193 Maleic Anhyd. 55. 0 1a 1, 200 140 163 1, 032 193 Phthalic Anhyd. 83. 0 1a 1, 200 140 163 1, 032 190 Citraconic Anhyd.-- 61. 5 1a 1, 200 140 163 032 193 Aconitic Acid 97. 5 2a 2, 130 79. 0 147. 5 1, 140 197 Diglycolic Acid 69. 5 2a 2, 130 79. 0 147. 5 1, 140 200 Oxalic Acid 66. 1 2d 2, 130 79. O 147. 5 1, 140 202 M31810 Anhyd 52. 1 2a 2, 130 79. 0 147. 5 1, 140 197 Phthalic Anhyd 76. 8 2a 2, 130 79. 0 147. 5 1, 140 197 Oitraconic Acid 58. 0 2a 2, 130 79. 0 147. 5 1, 140 197 Aconitic Acid 90. 0 3a 3, 410 49. 5 103 1, 632 200 Diglycolic Acid 49. 1 3a 3, 410 49. 5 103 1, 632 198 Oxalio Acid 45. 9 3a 3, 410 49. 5 103 1, 632 200 Maleic Anhyd 35. 8 3c 3, 410 49. 5 103 1, 632 203 Phthalic Anhyd 55. 0 3a 3, 410 49. 5 103 l, 632 204 Oitraconic Anhyd 41. 9 3a 3, 410 49. 5 103 2 203 Aconitic Acid 64. 8 4a 5, 510 30. 5 77. 5 2, 175 203 Diglycolic Acid. 37. 6 4a 5, 510 30. 5 77. 5 2, 175 203 Oxalic Acid 35. 2 4a 5, 510 30. 5 77. 6 2, 175 208 Maleic Anhyd 28. 0 4a 5, 510 30. 5 77. 5 2, 175 208 Phthalic Anhy 42. 5 4 1 5, 510 30. 5 77. 5 2, 175 216 Citraconic Acid. 33. 4 4a 5, 510 30. 5 77. 5 2, 175 209 Aconitic Acid--. 50. 0 5a 7, 290 23. 2 61. 5 2, 742 202 Diglycolic Acid 29. 6 5c 7, 290 23. 2 61. 5 2, 742 210 Oxalic Acid. 28. 8 5c 7, 290 23. 2 61. 5 2, 742 204 Maleic Anhyd 21. 8 5a 7, 290 23. 2 61. 5 2, 742 210 Phthalic Anhyd. 34. 0 5a 7, 290 23. 2 61. 5 2, 742 200 Oitraconic Anhyd. 24. 4 5a 7, 290 23. 2 .61. 5 2, 742 204 Aconitic Acid 38. 8

TABLE 3 Maximum Ex. No. Amt. Esterifigg gf Water of Acid Solvent Solvent cation cation Out Ester (grs.) Teggp (hm) (cc.)

lb Xylene-methanol 258 141 2b d0 234 139 248 140 276 136 252 146 281 140 258 143 237 131 254 140 274 141 255 142 278 144 243 140 224 138 236 143 258 145 246 148 258 148 236 143 223 139 236 144 251 148 249 148 254 144 228 142 227 140 226 145 244 149 224 148 239 144 The procedure for manufacturing the esters sulfate is not precipitating out. Such salt should has been illustrated by preceding examples. If be eliminated, at least for exploration experifor any reason reaction does not take place in mentation, and can be removed by filtering.

a manner that is acceptable, attention should be directed to the following-details: (a) Recheck the hydroxyl or acetyl value of the oxypropylated derivative and use a stoichiometrically equivalent amount of acid; (b) if the reaction does not proceed with reasonable speed either raise the temperature indicated or else extend the period of time up to 12 or 16 hours if need be; (c) if necessary, use /2% of paratoluene sulfonic acid or some other acid as a catalyst provided that the hydroxylated compound is not basic; (d) if the esterification does not produce a clear product a check should be made to see if an in- Everything else being "equal, as the size of the molecule increases and. the reactive hydroxyl radical represents a smaller fraction of the entire molecule, more difficulty is involved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperature and long time of reaction there are formed certain compounds whose compositions is still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been made as to the nature of organic salt such as a sodium chloride or sodium these comp ch a being cyclic polymers of propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, 4. e., of an aldehyde, ketone, or allyl alcohol. In some instances an attempt to react the stoichiometric amount of a polycarb'oxy acid with the oxypro pylated derivative results in an excess of the car.- boxylated reactant for the reason that apparently under conditions of reaction less reactive hydroxyl radicals are present then indicated by the .hydroxyl value. Under such circumstances there is simply a residue of the carboxylic reactan't which can be removed by filtration or, if desired, the esterification procedure can be repeated using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value and conventional procedure leaves much to be desired :due either to the cogeneric materials previously referred to, or for that matter, the presence of any inorganic salts or propylene oxide. Obviously this oxide should be eliminated.

The solvent iemployed, if any, can be removed from the finished ester by distillation and particularly vacuum distillation. The final .products or liquids are generally pale amber, amber to reddish-black in color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. the purpose of demulsification or thelike color is not a factor and-decolorization is not justified.

,;In the above instance I have permitted the solvents to remain present in the final reaction mass. In other instances I have followed the same procedure using decalin or a mixture of decalinorbenzene in the .same manner and ultimately removed :all the solvents by vacuum distillation. Appearances of thefinal products are much the same as the polyols before esterification and in some instances were somewhat darker in colorand .had a reddish cast and perhaps were somewhatmore viscous.

PART 3 'In the hereto appended claims the demulsifyingagent is described as an ester obtained from a polyhydroxylated material prepared from a trian'ilne. If one were concerned with a mononydrox iated material or a dihydroxylated material ,one might be able to write a formula which in essence would represent theparticular product. However, in a more highly 'hydroxyl'ated material the problem becomes increasingly more diflicult for reasons which have alreadybeen indicated in connection with 'oxyp'ropylati'on and which can lief-examined -by merely considering for the monient a monohydroxylated material.

Oxypropylation' involves the same sort of varianonsas appear in preparing high molal polypropylene glycols. Propylene glycol has a secand y alcoholic radical and a prir'na-r-y alcohol radical. Obviously then polypropylene glycols could beobtained, at least theoretically,- in which two asecondarygalcoholic groups are united'or a secondary :alcohol groupais united to a primary alcohol ,group, etherization being ,involved, of course, in :each instance. Needless .tosay, the samevisituation ,appliesz'when one has oxypropylatedpoIy-hydric materials having 4 or moreuhy- However, for

glycol or the products obtained in the manner herein described one does not obtain a single derivative such as HO(RO)1LH or -(RO)1LH i which n has one and only one value, for instance, 14, 15 or 16, or the like. Rather, one obtains a cogeneric mixture of closely related or touching homologues. These materials invariably have high molecular weights and cannot be separated from one another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various individual members of the mixture. On a statistical basis, of course, n can be appropriately specified. For practical purposes one need only consider the oxypropylation of a, monohydric alcohol because inessence this is substantially the mechanism involved. Even in such instances where one is concerned with a monohydric reactant one cannot draw a single formula and say that by following such procedure one can readily obtain or or of such compound. However, in the case of at least monohydric initial reactants one can readily draw the formulas of a large number of compounds which appear in some of the probable mixtures Or can be prepared as components and mixtures which are manufactured conventionally.

Simply by way of illustration reference is made to the copending application of De Gr'oote, Wir-t'el, and Pettingill, Serial No. 109,791, filed August 11, 1949 (now Patent 2,549,434, granted April 1'7, 1951).

However, momentarily referring again to a monohydric initial reactant it is obvious that if one selects any such simple hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylations, or oxypropylation, one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RG(C2H40)3oOI-I. Instead, one obtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following, RO(C2H4O)1LH, wherein n, as far as the stat-istical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point'where n may represent 35 or more. Such mixture is, as stated, aco'generic closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cog'eneric condensation products of the "kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration a d ,how to repeat such production time after time without difilculty, it is necessary to resort to some other method of description, or else consider the Value of n, in formulas such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the assumption of completeness of reaction.

This may be illustrated as follows: Assume that in any particular example the molal ratio of propylene oxide per hydroxyl is to 1. In a generic formula 15 to 1 could be 10, or some other amount and indicated by 12. Referring to this specific case actually one obtains products in which 1:. probably varies from 10 to 20, perhaps even further. The average value, however, is 15, assuming, as previously stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines herein described is that in the initial stage they are substantially all watersoluble, for instance, up to a molecular weight of 2,500 or thereabouts. Actually, such molecular weight represents a mixture of some higher molecular weight materials and some lower molecular weight materials. The higher ones are probably water-insoluble. The product may tend to emulsify or disperse somewhat because some of the constituents, being a cogeneric mixture, are water-soluble but the bulk are insoluble. Thus one gets emulsifiability or dispersibility as noted. Such products are invariably xylenesoluble regardless of whether the original reactants were or not. Reference is made to what has been said previously in regard to kerosene-solubility. For example, when the theoretical molecular weight gets somewhat past 6,000 or at approximately 7,000 the product is kerosene-soluble and water-insoluble. These kerosene-soluble oxyalkylation products are most desirable for preparing the esters. I have prepared hydroxylated compounds not only up to the theoretical molecular weight shown previously, i. e., about 8,000 but some which were much higher. I have prepared them, not only from dipropylenetriamine, but also from oxy-ethylated or oxybutylated derivatives previously referred to. The exact composition is open to question for reasons which are common to all oxyalkylations. It is interesting to note, however, that the molecular weights based on hydroxyl determinations at this point were considerably less, in the neighborhood of a third or a fourth of the value at maximum point. Referring again to previous data it is to be noted, however, that over the range shown of kerosene-solubility the hydroxyl molecular weight has invariably stayed at two-thirds or five-eighths of the theoretical molecular weight.

It becomes obvious when carboxylic esters are prepared from such high molecular weight materials that the ultimate esterification product again must be a cogeneric mixture. Likewise, it is obvious that the contribution to the total molecular weight made by the polycarboxy acid is small. By the same token one would expect the efiectiveness of the demulsifier to be comparable to the unesterified hydroxylated material. Remarkably enough, in many instances the product is distinctly better.

the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent,

20 such as water, petroleum hydrocarbons, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the

material or materials employed as the demulsi-i fying agent of my process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well-known classes of demulsifying agents.

It is well known that conventional demulsifyin agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oiland water-solubility. Sometimes they may be used in a form which exhibits relatively limited oil-solubility. However, since such reagents are frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice, such an apparent insolubility in oil and water is not significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material of materials employed as the dem'ulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemi-' cal reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in a tank and conduct a batch treatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for examplejby' agitating the tank of emulsion and slowly dripping demulsifier into the emulsion. In some cases mixing is achieved by heating the emulsion while dripping in the demulsifier, depending upon the. convection currents in the emulsion to produce satisfactory admixture. In a third modification of this type of treatment, a circulating pump withdraws emulsion from, e. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the de.-, mulsifier is introduced into the well fluids at the well-head or at some point between the well-head and the final oilstorage tank, by. means of an adjustable proportioning mechanismor".proportioning pump. 1 Ordinarily the flow of fluids through the subsequent lines and fittings sufiices to produce the desireddegree' of mixing of de-' mulsifier and emulsion, although in someinstances additional mixing devices ma be introduced into the flow system; In this general procedure, the system may include various mechahi cal devices for withdrawing free water, separat ing entrained water, or accomplishing quiescent settling of the chemicalized 'emulsion, Heating 21 devices may likewise be incorporated in any or the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier' to emulsion is to introduce the deniulsifier either periodically or ontinuously in diluted or undiluted form into the Welland t allow it to come to the surface with the well fluids, and then to flow the 'chemieaiiz'eo emul sion through any desirable surface equipment,

such as employed in the other treating procedures.

This particular type of appncation is decidedly useful when the dernnlsifier is use in connection with acidification or calcareous oi -bearing strata, especially if suspended in or dissolved in the acid employed for acidification. I r

In all cases, it will be apparent from the fore-- going description, the broad process consists simply in introducing a relatively small pro er: tion or demuisifier into a relatively iarge pro portion of emulsion, admixing 'the'cheini'cal and emulsion either through natural flow or through special apparatus, with or without the appiica= tion of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is atypical installation.

A reservoir to hold the demulsifierof the kind described (diluted or undiluted) is placed at the wen-mead where the efflue'nt liquids leave the wen. This reservoir or container, which may vary from gallons 'to 50 gallons for convenience, is com nected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving "the well. Such chemicalized 'fluids pass through the fiowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts of fluid produced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular conduit from the top of the tank to almost th very bottom so as to permit the incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluids do not disturb Stratification which takes place during the course of demulsification, The settling tank has two outlets, one being below the water level to drain off the water resulting from de--'- mulsification or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit or pipe which serves to carry the fluids from the well to the settling tank may include a section of pipe with baflies to serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids, or a heater for raising the temperature of the fluids to some convenient temperature, for instance, 120 to 150 F., or both heater and mixer. v

Demulsification procedure is started by simply setting the pump so as to feed a comparatively large ratio of demulsifier, for instance, 1:5,000. As soon as a, complete break or satisfactory demulsiflcation is obtained, the pump is regulated until experience shows that the amount of demu-l sifier being added is just suflicient to produce clean or dehydrated oil. The amount being fec l at such stage is usually 1:-10,000-, irl-5,000, 1:20,000, or the like.

In -many instances the oxyalkylated products herein specified as demulsifiers can be conven iently used without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. For instance, by mixing '15 parts by weight of the product of Exam le 2511 with 15 parts by weight of xylene and 10 parts by weight of isopropyi alcohol, an excellent demul either is obtained. selection of the solvent will vary, dependingnpon the solubility eharaoteri= tics of the 6X a-lkylated product, and or co will be dictated in part by economic consioerae tier-is, i. er, cost.

As notedabove, the products he! described may be used not only in diluted rein-1, but also may be used admixed with some other chemical derrr'ulsinerr A mixture Whieh illustrates such combination isithe followin o-izyallrylatedderivative, for example, the prodnet or Example 25b, 20%;

A cyclohexylamine salt or a polypropylated naphthalene nionosuironie acid, 24%;

ammonium salt of a polyproylated naph 'thalene inohosulfdiiic acid, 24%;

A sodium salt of ell-soluble mahogany etro= learn sul fohic acid, 12%;

n high-boiling aromatic petroleum solvent. 15%;

isopropyi alcohol, 5%.

:lhe above proportions are all weight percents.

Having thus described my invention, what I claim as new and desire to obtain by Letters Pateht,

1 A process ior breaking petroleum emulsions of the water in oi l type characterized by subjectihg the einulsion'to the action of a demulsifiei" including hydrophile synthetic products; said hydrophil'e synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts. and acidic amido' derivatives obtained by reaction between (A) apolycarbox acid, and (B) high molai o'x propylation derivatives of monomeric t rliiimiho compounds, with the proviso that (a) the initial tri'amino reactant be 'free from any radical having at least 8 uninterrupted carbon atoms,- (b) the initial triamino reactant have a molecular Weight of not over 800 and at least a lurality of reactive hydrogen atoms; (c) the initiai triain'ino reactant must be water-soluble; or) the osry ropyiatjion end product must be waterin's'ol'uhle, and kerosene soluble; (e) the oxypropylaition end product be within the molecular weight ran e of 2500 to 30,000 on an average stati'stical basis; (If) the-solubility characteristics of the oxypropy I, on end product in respect to Water and kerosene must be substantially the result of the ,oiiypropylation step; (g) the ratio of propylenegXide per initial reactive hydrogen atoin must be'wi'thin the range or 7 to 70:; (h) the ihitialtriamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (1') the preceding provisos are based on the assumption'of complete reaction involving the proylene oxide and initial triamino reactant; (9 the nitrogen atoms are linked by a propylene chain, and with the final proviso that the ratio of (A) to '(B) be one mole of (-A) for each reaetive hydrogen atom present in (-B).

2. A process for breaking petroleum emulsions of the water-i-n-oil type characterized by subjccting the-emulsion to theactionof a demulsifler including hydrophile synthetic products; said hydrophilesynthetic products being a cogener-ic mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amino derivatives obtained by reaction between (A) a polycarboxy acid and (B) high molal oxypropylation derivatives of monomeric triamino compounds, with the proviso that (a) the initial triamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial triamino reactant having a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the initial triamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2500 to 30,000 on an average statistical basis; (f) the solubility characteristics of the'oxypropylation end product in respect to water and kerosene must be substantially the re-' sult of the oxypropylation step; (9) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of 7 to 70; (h) the initial triamino reactant must represent not more than 20% by Weight of the oxypropylation end product on a statistical basis; (2') the pre-' ceding provisos are based on the assumption'of complete reaction involving the propylene oxide and initial triamino reactant; (7') the nitrogen atoms are linked by a propylene chain; (It): at least one of the nitrogen atoms be basic, and with the final proviso that the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B). I

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by-subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained by reaction between (A) a polycarboxy acid and (B) high molal oxypropylation derivatives of monomeric triamino compounds, with the proviso that (a) the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial triamino reactant have a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the initial triamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecularweight range of 2500 to 30,000 on an average sta tistical basis; (1) the solubility characteristics of the oxypropylation end product in respect to Water and kerosene must be substantially the re sult of the oxypropylation step; (9) the ratio of propylene oxide per initial reactive hydrogen atom mustbe within the range of 7 to 70; (h) the initial triamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (2') the'precedingprovisos are based on the assumption of complete reaction involving the propylene oxide andinitial triamino reactant; (7') the nitrogen atoms are linked by a propylene chain; (It) that at least two nitrogen atoms be basic; and with the final proviso that the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B).

4. A process for breaking petroleum emulsions" of the water-in-oil type characterized by 'subjecting the emulsion to the action of a demulsifler' including hydrophile synthetic products; saidhydrophile synthetic products being a cogen'eric mixture selected from the class consisting oi acidic fractional esters, acidic ester. salts, and

acidic amido derivatives obtained by reaction between (A) a pclycarboxy acid free from any radical. having more than 8 uninterrupted carbon atoms in a single group, and (B) high molal oxypropylation derivatives of monomeric triamino compounds, with the proviso that (a) the initial triamino reactant be free from any radical having at least 8 uninterrupted carbonatoms; (b) the initial triamino reactant have a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the initial triamino reactant must be water-soluble; (d) the oxypropyl-ation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2500 to 30,000 on an average statistical basis; (1) the solubility characteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result'of the oxypropylation step; (g) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of '7 to 70; (h) the initial triamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial triamino reactant; (7') the nitrogen atoms are linked by a propylene chain; (k) that at least two nitrogen atoms be basic; and with the final proviso that the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B).

. 5. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydro'phile synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained by reaction between (A) a dicarboxy acid free from any radical having more than 8 uninterrupted carbon atoms in a single group, and (B) high molal oxypropylation derivatives of monomeric triamino compounds, with the proviso that (a) the initial triamino reactant be free from any radical having at least'8 uninterrupted carbon atoms; (b) the initial triamino reactant having a molecular weight of not over 800 and at least a plurality ofreactive hydrogen atoms; 1 (c) the initial triamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2500 to 30,000 on an average statistical basis; (1) the solubility characteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation; (g) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of 7 to 70; (h) the initial triamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (2) the preceding proviso's are based on'the assumption of complete reaction involving the propylene oxide and initial triamino reactant; the nitrogen atoms are linked by a propylene chain; (10) that at least two nitrogen atoms be basic; and with th final proviso that the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B).

6. A process for breaking petroleum emulsions of the water-in-oil type characterized by sub- 25 26 jecting the emulsion to the action of a demulsifier '7. The process of claim 6 wherein the dicarincluding'hydrophile synthetic products; said hyboxy acid is diglycollic acid. drophile synthetic products being a cogeneric 8. The process of claim 6 wherein the dicarmixture selected from the class consisting of boxy acid is maleic acid. acidic fractional esters, acidic ester salts, and 9. The process of claim 6 wherein the dicaracidic amido derivatives obtained by reaction beboxy acid is phthalic acid.

tween (A) a dicarboxy acid free from any radical 10. The process of claim 6 wherein the dicarhaving more than 8 uninterrupted carbon atoms boxy acid is citraconic acid.

in a single group, and (B) high molal oxypropyla- 11. The process of claim 6 wherein the dicartion derivatives of dipropylenetriamine, with the 10 boxy acid is succinic acid.

proviso that (a) the oxypropylation end product his must be water-insoluble and kerosene-soluble; MELVIN X DE GROOTE. (b) the oxypropylation end product be Within the mark molecular weight range of 2500 to 30,000 on an Witnesses to mark:

average statistical basis; (0) the solubility char- 15 W. C. ADAMS,

acteristics or the oxypropylation end product in I. S. DE GROOTE.

respect to water and kerosene must be substantially the result of the oxypropylation step; (12) REFERENCES CITED the ratio of propylene oxide per initial reactive The following references are of record in the hydrggen atom must be within the range of: 7 20 file f this patent:

to 7 (e) the initial triamino reactant must represent not more than 20% by weight of the UNITED STATES PATENTS oxypropylation end product on a statistical basis; Number Name Date (I) the preceding provisos are based on the as- 2,243,329 De Groote et a1. May 27, 1941 sumption of complete reaction involving the pro- 2,295,169 De Groote et al. Sept. 8, 1942 pylene oxide and initial triamino reactant; and 2,562,878 Blair Aug. 7, 1951 with the final proviso that the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B). 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS BEING A COGENERIC HYDROPHILE SYNTHETIC PRODUCTS BEING A COGENERIC MIXTURE SELECTED FROM THE CLASS CONSISTING OF ACIDIC FRACTIONAL ESTERS, ACIDIC ESTER SALTS, AND ACIDIC AMIDO DERIVATIVES OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID, AND (B) HIGH MOLAL OXYPROPYLATION DERIVATIVES OF MONOMERIC TRIAMINO COMPOUNDS, WITH THE PROVISO THAT (A) THE INITIAL TRIAMINO REACTANT BE FREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (B) THE INITIAL TRIAMINO REACTANT HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE INITIAL TRIAMINO REACTANT MUST BE WATER-SOLUBLE; (D) THE OXYPROPYLATION END PRODUCT MUST BE WATERINSOLUBLE, AND KEROSENE SOLUBLE; (E) THE OXYPROPYLATION END PRODUCT BE WITHIN THE MOLECULAR WEIGHT RANGE OF 2500 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (F) THE SOLUBILITY CHARACTERISTICS OF THE OXYPROPYLATION END PRODUCT IN RESPECT TO WATER AND KEROSENE MUST BE SUBSTANTIALLY THE RESULT OF THE OXYPROPYLATION STEP; (G) THE RATIO OF PROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM MUST BE WITHIN THE RANGE OF 7 TO 70; (H) THE INITIAL TRIAMINO REACTANT MUST REPRESENT NOT MORE THAN 20% BY WEIGHT OF THE OXYPROPYLATION END PRODUCT ON A STATISTICAL BASIS; (I) THE PRECEDING PROVISOS ARE BASED ON THE ASSUMPTION OF COMPLETE REACTION INVOLVING THE PROPYLENE OXIDE AND INITIAL TRIAMINO REACTANT; (J) THE NITROGEN ATOMS ARE LINKED BY A PROPYLENE CHAIN, AND WITH THE FINAL PROVISO THAT THE RATIO OF (A) TO (B) BE ONE MOLE OF (A) FOR EACH REACTIVE HYDROGEN ATOM PRESENT IN (B). 